Drop-bridge



'Y posts or bents, above the surface when re-y iiNrrrzD STATENT OFFICE. i

J. D. WOODRUFF, OF NEWARK, AND J. H. BUTTERWORTH, or DOVER, NEW iEnsEY.

DROP-Eamon.

Specification of Letters Patent No.' 101,527, dated February 14, 1354-..

To all whom t may concern Be it known that we', J Aoo D. WOODRUFF, of the city of Newark, in the county lof Essex and State of New Jersey, and JOsi-IUA H. BUTTERWORTH, of Dover, in the county of Morris, inthe same State, have invented a new and Improved Mode of Constructing Bridges and Draws; and We do hereby declare that the following isv a full and exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon.

The leading idea of our invention consists 11i placing the bridge vor draw under water, and raising it, atwill, by means of movable quired for use. When not in use, vessels can pass over it Without obstruction, and the bridge or draw itself may be rendered secure from the passage of ice, and from the ravages of lire.

To enable others skilled in the architecture and construction of bridges, to make and-use our invention, we will proceed to describe its construction and operation. For this purpose, reference will be made to the accompanying drawings as above stated.

Figure l, is a plan of the bridge or draw as the same would appear to a person ele- Vated directly above the same. Fig. 2 is an elevation or side view, thereof. Fig. 3

is an end view; and Fig. 4 represents one o-f the movable bents on which the bridge is to rest.

The same letters in all the figures repre'- sent the same parts.'

In the first place, sills, A, A, are to be embedded in the bottom of the stream, or

framed upon piles, at the depth desired, and

to extend across the stream or channel to be spanned. There must be at least two lines of sills, one on each side of the bridge. They should be properly strengthened by cross braces, or cross sills, as seen in B, B, Figs. 3 and 4, and also by piles or fenders if the rapidity of the current, or other circumstances should require it. The sills formv are to be of suilicient height, when erect,

i to give the bridge a proper height above', the

surface. The kposts are tobe arranged in pairs, the two posts in each pair being attached, opposite to each other, one to one sill, and the other to the opposite sill. A

cross-beam, D, D, Figs. l and 4, connectsv them, thus forming a bent. The bent thus formed by Imeans of the pivotsconnecting the feet ofthe posts tothe sills, maybe loweredy so as vto rest on the sills, or may be raised kto an upright vposi-tion at pleasure.

The pivots connectinfr into this shaft, will revolveon the pivots, as

thebent is loweredor raised.

A series of bents formed as above described, and placed at proper distances from each other for supporting the bridge, is

the feet of the posts with the Sais are best formed by construct, ing a beam or shaft, (E, E, Figs. l, 3 and erected along the ground-sills, A, A, from` Y oneeXtremity of the bridge or draw tothe other. The bridge if of considerable length, v

mustbe formed in sections, each section `to be supported by two orfmore bents. A draw will in general require but a single section.v

Each section is formed as follows The bents, (two in number for example) beingy I brought to an upright position, string-pieces `are .laid across the, 1bents,` longitudinally? withvthe bridge, inside of the posts. Theyl are designated by the let-ters F, Figs. 1,2 & 4. These string-pieoes are attached'to the bents by strongiron straps, r, 1', firmly fastened to the underside ofthe stringpiece,

vand passing around the'cross-beam. ofthe bent, which is rounded at that place for the purpose. The strap must not Vfit sortightly y v to the cross-beam, but that the lattery may turn in the strap whenthe bent isin motion.

The string-piecesbeing thus attaclied'to the bents, it is evident that the whole sec-V tion will risev and'fall with the bents. In this way each section of the bridgecamin a few seconds be'placed at a sufficient .depth below thesurface of the waterto allowves- .sels of any draft topass over it; and may again at will bey elevated. to a s'uiieient Y Y height above the surface for the passage of passengers, carriagesor railroad cars.. The

bents and string-pieces, when resting atft1 ie L l bottom of the` river, are represented by dotted or V*broken lines, and by the letters, C', C', and F', F', in Fig. V2; the broken line Gr, being intended to represent the surface of the water. 1

The mode of raising and lowering the different sections is by a windlass .and chains, the windlass being constructed on the piers or permanent portions of the bridge. `The windlass is designated in Figs. l, 2 and 3 by the letter H, with a crank, letter I; and the chains are designated in Figs. 1 and 2 by the letters, K, K, L, L. The middle chain, L, passes from the windlass downward around the pulley S, thence, along the bottom of the river, around the pulley S', and thence, upward to the cross-beam of the bent on the farther side of the draw; to which it is attached. This chain is for the purpose of pulling the drawn down, and winds around the Vwindlass in an opposite direction to the chains K, K. The latter chains K, K, pass upward from the windlass around the pulleys, t, t, and from` thence to the posts or cross-beam, of the bent nearest to the windlass, to which it is attached. These chains are for the purpose of raising the draw up, when it is under the water.

The windlass may be operated by steampower, horse or other power, or by hand according to convenience, and the measure of power required.

The draw locks into the permanent part of the bridge in the manner shown by reference to the letters, m, n, and m', n', Fig. 2. The end of each string-piece of the draw is cut away onthe upper side, sov that the lower half thereof projects beyond the upper half; and when the drawis raised to its place a corresponding projection on the upper Side of the string-piece of the stationary pier or bridge laps'and fits into the notch or shoulder thus formed. The string-piece that the end neXt to the draw can be raised in the position shown by the `broken lines at M", being kept in its place by a pivot, or

large bolt, 0, which serves as a pivot for that purpose. As the draw is raised up out of the water, the end n', of the string-piece F, when it comes in contact with the stringpiece M', raises it up, unless it has been previously raised by a` lever or machinery arranged for that purpose, until the draw comes to its place in a perpendicular position, when the spring-piece M', falls into the notch, making the jointas seen at m', n', and keeping the draw iXed firmly in its position.

When it is desired t0 lower the draw again, the string-piece M', is raised to -the position seen at M", by'means of a leverV N, having an arm O, and turning on a pivot n. This lever N, being drawn forward to the position, N', the arm, O, is raised upward to theposition, O', and thereby raises the string-piece, M', under Vand against which the arm,^O, rests. The lever, N, is drawn forward bymeans of the chain, or rope P;

Vwhich is attached to the lever Q, passed downward therefrom, around the pulley, fw,

and is attached'to the lever, N, at the point o. By forcingdown the opposite end of the lever Q, `the end-thereof to which the chain is attached, is forcedupward` (as seen inY Q) Vand the chain P drawsthe lever, N, forward to the position N', as required. This arrangement enables one operator, standing on the side of the draw next to the windlass, to raise and lower the draw.

A similar apparatus is, of course, required for each string-piece of the draw, unless the st-ring-piece, M', and its fellow are framed i together by means of cross-timbers so that the raising of one necessarily raises the other. s

A railing can be formed by producing the posts three' or four feet above the stringpieces, and stretching thereon a chain` or iron rod through rings attached by staples to theedge of the posts which lies upward when resting at the bottom of the river.

When the bridgeor draw is formed of two n or more sections, instead of one, each succeeding section follows and fits into the one that precedes it in the same manner that a draw of one section fits into the pier'or stationary part of the bridge. Again, if it is desired that the draw should be formed of two sections, so that one section shallfall outward one way and the other fall outward the other, leaving a greater depth in the center or channel, this object can easily be attained, by a double set of fixtures as above described. VIn that case the stringpieces of the pier on both sides of the draw should be movable, so as to be capable of being raised up, to let the` sections of the draw on each side respectively drop back under the pier.

It may be observed that the string-pieces `M, and M', are supported, when the draw is up and in use, by the posts ofthe draw,and that they project beyond the posts of the stationary part of the bridge suiiiciently far, to give the draw in its upward and downward motion, abundant, room for that purpose,

without being obstructedby the stationary than the width of the bridge or draw, so that the posts of each bent may lean toward each other when t-he bents are raised to a perpendicular posit-ion. This arrangement, we think, will add strength to the work.V Itis not necessary for any other purpose.

Of course the size of the timbers, and the height of the posts will entirely depend upon the particular circumstances of every case-to be decided by the good sense of the engineer.

Where the water is stationary, `the posts need to be no longer than may be necessary to raise the bridge or draw sufficiently above the surface of the water for convenient travel, and to lower it to a suflicient distance below the surface for convenient passage of vessels. Thus, suppose the grade of a road requires that the bridge or draw, when used,

which maybe dropped below the surface of the water, so as to admit the passage of vessels over the same, substantially as above described. f

JACOB D. WOODRUFF. JOSHUA H. `BUTTERVVORTHl Vitnesses:

JosIAH MEEKER, A. S. BURTT. 

